Connection for shafts and hubs.



p A d R I] N o T N A L B A L l 5 7 0O 4 6 U N CONNECTION FUR SHAFTS AND HUBS.

(Application filed Apr. 19, 1898.]

(No Model.)

1 Wu we no shows an embodiment of my invention as ap UNITE STATES PATENT OFFICE.

EnwARnA. BLANTON, JR, OF RIDLEY PARK, PENNSYLVANIA.

CONNECTION FOR SHAFTS AND HUBS.

SPECIFICATION forming part of Letters Patent No. 648,352, dated April 24, 1900.

Application filed April 19, 1898. Serial No. 678,177. (No model.)

To aZZ whom it may concern:

Be it known that I, EDWARD A. BLANTON,

J r., a citizen of the United States, residing at Ridley Park, in the county of Delaware and State of Pennsylvania, have invented certain new and useful Improvements in Connections for Shafts and Hubs, of which the following is a specification.

My invention relates to means for securing hubs, sleeves, and similar devices to shafts and the like, and has for its object to provide means whereby what is generally known as a forced fit between the parts may be secured in a substantial and improved manner and whereby the objections to such constructions can be avoided; and to these ends my invention consists in the various features of construction and arrangement of parts, substantially as hereinafter more particularly set forth. g

In the accompanying drawings, Figure 1 plied to a propeller-blade and shaft, the parts being displayed in perspective for purposes of clearness. Fig. 2 is a longitudinal vertical section, on an enlarged scale, showing the parts assembled, the blades being broken away. Fig. 3 is a plan view of the hub, on an enlarged scale, parts being broken away; and Fig. 4 is a longitudinal vertical section showing a modification.

In my PatentNo. 581,476, granted April27, 1897, I have shown, described, and claimed a means for securing cams or hubs upon shafts, in which, among other things, the shaft was provided with a series of curved wedge-shaped bosses arranged in a circumferential line around the shaft and the hub was provided with a similar series of recesses or bosses and was adapted to be tightened upon the shaft by turning 'on said bosses, and in my Patent No. 601,232, granted March 29, 1898, I have shown, described, and claimed an extension of this broad invention whereby the general principles thereof are adapted to a coupling for shafts and similar devices, and in my application, Serial No. 666,935, filed January 17, 1898, I have shown a further extension of the general principles of the invention in connection with the use of filling-pieces, and my present invention may be said to be a further improvement and extension of the broad prinforced fit, and in these constructions the opening in the hub or sleeve and portion of the shaft or other construction to which the hub is applied is usually made tapering, and this kind of attachment is used for many and various purposessuch, for instance, as attaching a propeller-blade to its driving-shaftand I will illustrate my invention in connec tion with such a construction, although, of course, it will be understood that the invention can be applied to many and various uses for which it is adapted by those skilled in the art without departing from the spirit of the invention.

In the drawings, A represents the shaft or other device to which the hub or sleeve of a propeller, pulley, or other similar construction is to be attached. The end A is shown as being tapered longitudinally toward its end, and it is provided with a series of wedgeshaped portions at, extending longitudinally of the tapered surface and arranged circumferentially around the same and preferably occupying the whole of the circumference. The tapering portion A of the shaft may be provided with any desired number of wedge- .shaped portions a, according to the size and the wishes of the constructor, there being shown ten in the present instance, which I have found to be a satisfactory number in most instances, and these wedge-shaped portions are of uniform size, although of course they may be of varying sizes and be variously arranged with relation to each other. The outer surfaces of these wedge-shaped portions or bosses a are preferably on curves having gradually-increasing radii measured from the center of the shaft, either in the form of true eccentrics or involute curves or otherwise, while the point of junction between the high part of one wed ge-shaped portion and the low part of another is preferably curved, forming 2. I r v v I b45352 shape of this portion can be variedwithout materially affecting the essence of the invention. It will'thus be seen that in the embodiment shown there are a series of longitudinally-tapering curved portions or bosses at,

arrangedor formed symmetrically on the tapered portion A of the shaft, and at the point i of junctionof-these tapered portions with the main body of the shaft I find-it convenient tomake a groove A of a depth correspondsponding substantially with the taper of 'the curved portions'or bosses on the shaft and is.

' provided wit-ha series of recessesorbosses b,

1 the counterpart of. the curved .portions- :or

" bosses a on the shaft.

12- ofthe recesses are made to'correspond'p'rac tically with the outer curved surfaces on the shaft, and the lowportions b are the-counterpart of the high portions, and the curve join-' in}; the high and low portions of the recesses is similar to the curve joining the high and low portions of the bosses onthe shaft, so that when the hub is in place on the shaft it 'will' accurately fit the same, resulting in an even pressure or strain throughout all parts of the hub, avoiding the tendency to burst the same through uneven stresses. The recess is of such asize with relation to the tapered por-- tion of the shaft that the hub can beslipped thegreater portion of its length into position without difficulty, and in applying the parts to each otherit is preferable to arrange them so 'thatthe highportions of the shaftwill fit and bear against the low portions 19 of the 3 recesses, the bosses on the hub leaving'a clearance between theouter curved portions of the shaft and the curved surface I) of the hub,"and:

. i as the tapered portion of the shaftenters the hub this clearance is gradually taken up and the hub. becomes self-tightening vupon the shaft and the two can be forced together under a moderate pressure, if desired, securing J a practical and substantial forced fit.

" der to maintain the parts in this position',

some means of external attachment may beused, andI have shown onesimple'means comprising the washer 0, adapted to fitithe squared portion A and set-nuts l) D, adap t.-' ed. to fit the screw-threaded portion 'A of the I shaft, and while inmany instances this i'snot' necessary in other instances it isd'es'irable-to have some such means of attachment to prevent. any accidental-loosening'of the hub on U the shaft which would disturb the relations of the parts.

ple of' the useofmy invention, vWhereinthe shaft A has a longitudinally-tapering portion The curved surfaces In'or-i A and the hub" B has a correspondingly tapering socket and is provided with a coupling-piece E, having wedge-shaped portions both internally and externally and adapted to fit the tapered portion of the shaft;

. It is not deemed necessary. to show other applications of the invention, as the general principles thereof will beclearly understood from what has been, set forth,-and perhaps it may be well to briefly set forth some of the,

advantages of this constru ction over the wellknown means of applyinghubs orsleeves in a somewhat. similar way.

In an ordinary forced fitbetween a tapering shaft and hub the parts areheld together and driven s'imply'by friction betweenthe two surfaces, and if forfany reason the parts changetheir relative pos'itions'in any, manner 'theybecome quite'freeandfthe're is no condition present which tends to restore the parts to their locking p'osit'i'on's,and this kind of a conical-forced fit is not'pos'itive and is unreconnection; but any change in the relative longitudinal positions of the parts will result in 'slackness and lost motion, and this lost .*mo,tion,.as in a case Whereno key is used, will resultin wear on the bearing-surfaces of all the parts, including the key, and therefore in gradual increase of the lost motion, and these would react on each other and continue until thestresses resulting-fromthe pressure of lost hydraulic or-screw pressure necessitatesfgreat accuracy vin the boring and turning of the parts to'be assembled and requires heavy and bulky machinery, and as this often has to be I done after the parts are assembled for direction at its destination it is further objectionable.

a. .With myvimproved form-that is, with a number of bosses or with curved facesequally distributed around the periphery of the tapered portion of the shaft and corresponding bosses or recesses in the hub-the conditions are entirely changed; L In the first place the connection between, the two parts is absolutely positive regardless of the direction of rotation, and thiswithout the addition of any third part, and in the event of any change taking place in the relativelongitudinal .posi- -tions of the two parts within certain. limits, depending upon the degree of the taper, size a. I 9 of cam, &c., the connection is self-tightening. In'Fig. ,4 I have illustrated another exam This istrue inbothdirections of rotation, for

face I) of the hub have a longer bearingsurface and more gradual tightening eifect the curved portions between the high and low parts of the bosses a also act as self-tighten ing connections to a greater or less extent. 'It is to be observed that in many applications of the invention the direction of rotation is very largely uniform, although there may be occasion to reverse the direction of rotation of the shaft, and all this is provided for in my construction. It will be observed that my method of connecting the parts produces a complementary bosses similarly tapering,- substantially as described.

2. The combination of a hub and shaft having self-tightening bosses tapering longitudinally, the outer faces of which bosses are on curves having gradually-increasing radii, measured from the center of the shaft, the hub being provided with a coupling-piece having complementary bosses similarly tapering, substantially as described.

3. The combination with a shaft having selftightening bosses tapering longitudinallythe outer faces of which bosses are on curves having gradually-increasing radii, measured from the center of the shaft and arranged circumferentially around the shaft, of a hub havin g complementary bosses similarly tapering, and mechanical means for securing the two together, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

EDWARD A; BLANTON, JR.

Witnesses:

' H. B. COLLINS,

ROBERT L. MORGAN. 

